1. Field of the Invention
The present invention relates to a variable thrust nozzle system capable of continuously and differentially varying its thrust to be exerted on a flying object.
2. Description of the Related Art
A known attitude and diversion controller for controlling the attitude and diversion of a flying object flying at high altitudes makes outside nozzles attached to an airframe of the flying object jet a high-temperature high-pressure gas to control the attitude and diversion of the flying object about five axes without using aerodynamic force.
FIGS. 12 and 13 show a basic thrust generating mechanism for this known attitude and diversion controller. The thrust generating mechanism has four nozzles 30 each having a throat 31, and four nozzle plugs 32 combined respectively with the nozzles 30. Each nozzle plug 32 opens and closes the corresponding throat 31 to control the flow of a gas through the corresponding nozzle 30. Therefore, the thrust generating mechanism needs one actuator for each nozzle 30. An excessively large force is necessary for closing the nozzles 30. The attitude and diversion controller operates in a PWM (pulse width modulation) control mode for a fast-response control operation. Accordingly, the attitude and diversion controller is large and has a complicated configuration. This known attitude and diversion controller has difficulty in continuously or differentialy varying the sectional area of the throat 31 of each nozzle by the operation of the nozzle plug 32, so that the attitude and diversion controller has difficulty in continuously or differentially varying the thrust of the gas jetted through each nozzle 30.